Why Cancer Screening May Not Be a Good Idea for the Elderly

Our risk of cancer rises dramatically as we age — cancer is, after all, a disease of aging, a consequence of our increasing longevity. So it makes sense that the elderly should be routinely screened for new tumors — or doesn’t it?

A new survey shows that the majority of nearly 19 million Americans over age 75 dutifully get screened for breast, prostate, and colon cancers each year. The study, published in the Archives of Internal Medicine, examined data on more than 50,000 middle-aged and elderly adults, and found that 62% of women aged 75 to 79 had received a mammogram in the past two years, while 53% of women the same age had received a pap test for cervical cancer within the past three years.

Among men aged 75 to 79, 56% were screened for prostate cancer. Overall, 57% of all adults aged 75 to 79 got colon cancer screens. The rates of screening dropped after age 80, but remained relatively high, with 50% of women getting mammograms and 38% receiving cervical cancer screens.

While such vigilant tracking of cancer is a good thing in general, researchers are increasingly questioning whether all of this testing is necessary for the elderly. Depending on a person’s health status and remaining life expectancy at age 75, screening to pick up emerging new cancers, which could take decades to grow, may not be of much benefit. As Dr. Locovico Balducci, a cancer expert at the Senior Adult Oncology Program at the Moffitt Cancer Center, told ABC News:

For breast cancer, colorectal cancer and cervical cancer — the cancers for which screening has been proved to be effective — if a person has less than five years to live, then screening is not beneficial. But if it’s longer and if a patient can tolerate cancer treatment, they shouldn’t be denied screening.

With the percentage of people over age 65 expected to nearly double by 2050, it’s important to weigh the health benefits of screening against the risks and costs of routine testing. The United States Preventive Services Task Force recommends against routine screening for breast, prostate and colon cancer after age 74, and advises against screening for cervical cancer in women aged 65 or older.

In many cases, screening can lead to additional biopsies and surgeries to remove cancer, which can cause side effects, while the cancers themselves may be slow-growing and may not pose serious health problems in patients’ remaining years. But the message that everyone must screen for cancer has become so ingrained that when the USPSTF recommended in 2009 that women under 50 and over 74 stop getting routine mammograms, it caused a riotous backlash among doctors, patients and advocacy groups. If even one woman could be saved by getting screened, critics of the new guidelines argued, why shouldn’t all adults at any risk of developing cancer be screened?

It’s hard to uproot deeply held beliefs about cancer screening with scientific data. Certainly, there are people over age 75 who have had cancers detected by routine screening, and gained several extra years of life because of treatment. And clearly, people over age 75 who have other risk factors for cancer, such as a family history or prior personal experience with the disease, should continue to get screened regularly. But for the remainder, the risk of cancer, while increased at the end of life, must be balanced with other factors like remaining life expectancy.

The authors of the current study, led by Dr. Keith Bellizzi, an assistant professor of human development and family studies at the University of Connecticut, hope that doctors will start to look more closely at screening efficacy — especially considering the explosion of elderly that will soon swell our population — and make more objective decisions about who will truly benefit from screening. “Over 50% of physicians are continuing to recommend screening tests in older men and women,” Bellizzi told Reuters. “I’m hopeful that these findings will serve as a catalyst for an important dialogue that needs to take place.”

Bellizzi suggests that instead of simply assuming that screening is always beneficial for every patient, doctors start with an assessment of whether the patient is likely, given his or her current health, to survive another five years. If they are, screening, detection and treatment of cancer could be justified.

It’s not an easy calculation to make, but one that make sense for the whole patient. Dr. Otis Brawley, chief medical officer at the American Cancer Society, told HealthDay that screening everyone over age 75 is a “waste,” noting, “Many docs are ordering these tests purely to cover themselves. We need to think about the rational use of health care and stop talking about the rationing of health care.”

That means making some difficult decisions with elderly patients, and going against the misguided belief that when it comes to health care, more is always better.

Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.